1. Field of the Invention
The present invention relates generally to a shutter for use in a camera, and more particularly to a shutter that prevents reexposure due to rebounding of the sectors when the shutter is in the fully closed state.
2. Description of the Related Art
One camera shutter of the related art is shown in FIGS. 4-6, where a driving lever 26 is rotated by a rotor shaft of an actuator M. A driving pin 27 is mounted on the driving lever 26. A base plate 21 is provided with an elongate hole portion 21b. The driving pin 27 extends through the hole portion 21b and through through-holes 24b and 25b formed in sectors 24 and 25, respectively. The sectors 24 and 25 are mounted to pivot or swing about shafts 22 and 23, respectively. The driving pin 27 is so constructed that it makes sliding contact with the through-holes 24b and 25b. 
In the related art structure described above, when the shutter is fully opened as shown in FIG. 4, the driving pin 27 is in contact with one end portion of the hole portion 21b and the shaft 23 is at rest in contact with a recessed portion of the sector 24. As shown in FIG. 5, when the driving lever 26 is rotated by the rotor shaft of the actuator M, the driving pin 27 begins to move. The driving pin 27 moves away from the end portion of the hole portion 21b, and the motion of the driving pin 27 is transmitted to the sectors 24 and 25. When the shutter is fully closed, the driving pin 27 is in contact with the other end portion of the hole portion 21b as shown in FIG. 6, and the shutter opening 21a is closed by the sectors 24 and 25. When the driving pin 27 drives the sectors 24 and 25 to the fully closed state, the driving pin 27 collides against the other end portion of the hole portion 21b and bounces or rebounds off the end portion. Since the sectors 24 and 25 are interlocked with the driving pin 27, the rebounding of the driving pin 27 causes the sectors 24 and 25 to swing back and forth in the opening and closing directions.
Therefore, if the amount of overlap between the sectors 24 and 25 is small, the problem arises that the shutter opening 21a is repeatedly opened and closed a slight amount when in the fully closed state. As a consequence, there is the danger that light leaks through the shutter opening 21a and makes a reexposure. Accordingly, to prevent reexposure, the amount of overlap between the sectors 24 and 25 must be set to a large value. However, if the amount of overlap is made larger, this prevents reducing the size of the shutter. Furthermore, this makes it difficult to improve the shutter speed, because the shutter blades are made larger and are therefore heavier.
Accordingly, it is an object of the present invention to provide a camera shutter which prevents reexposure when the shutter is in a fully closed state and permits miniaturization of the shutter and improvement in shutter speed.
A shutter for use in a camera in accordance with the present invention has a shutter opening formed in a base plate, plural sectors capable of opening and closing the shutter opening, and an operating member driven by an actuator for operating the sectors. The operating member extends through through-holes formed in the sectors. The through-hole in at least one of the sectors is so configured that a gap is formed in the direction of movement of the operating member.
By such a structure, when the shutter speed is sufficiently accelerated and the shutter opening is closed, if the operating member bounces or rebounds, the gap formed in the sector through-hole prevents the sector from directly interlocking with bounce or rebound of the operating member. Instead, this sector can still move in the direction of closing the shutter opening owing to inertia. Accordingly, when the other sector or sectors interlock with the bounce or rebound of the operating member and move in the direction to open the shutter opening, the former sector keeps moving in the direction of closing the shutter. Therefore, even if the amount of overlap between the sectors at full closure is reduced to a minimum, no reexposure occurs. Consequently, the shutter blades and hence the whole shutter can be miniaturized. Furthermore, by reducing the size and hence the weight of the shutter blades, the shutter speed is improved.